Two wheels

These days, there is very little on a bike that can't be made from carbon fibre. Frames, forks, wheels, gear and brake levers, handlebars, even chainrings and saddles are all moulded from this super-tough polymer. Stiff, light and strong, it is seen as pretty much the ideal material for bikes. Though it is rapidly coming down in price, it remains expensive - hence its nickname "black gold" - a fact that has served only to reinforce its cachet, since cyclists are suckers for lustrous but costly new gadgetry.

There is just one problem with the carbon success story: by any other name, it is plastic. The carbon fibres that are woven into its structure gain their phenomenal strength by being embedded in resin derived from industrial petrochemical processing. It is not impossible to recycle carbon fibre, just as it is not impossible to recycle car tyres, but it is so difficult and expensive to do that practically no one bothers.

But there may be a solution to this conundrum. Amid the hullabaloo of the Tour de France coming to London, there is one event that will hardly register in most people's book, but it is conceivable that we will look back on it as the more significant event in cycling's history. On Friday July 6, the day before the Tour prologue in the Mall, a conference is taking place next door at Carlton House Terrace, at the Institute of Materials, Minerals and Mining, entitled "Materials in Bicycles".

No doubt carbon fibre will be much discussed, as well as some of the more exotic metals from which bikes can be manufactured, such as magnesium. But conference chair Carlton Reid hopes that it may be an opportunity to push up the agenda new "biocomposite" technologies. Reid's day job is editing the online bicycle industry magazine BikeBiz, a consistently fascinating source of news on cutting-edge developments in cycle manufacture. Here, for instance, I first learned that a bike branded in the name of former Belgian professional Johann Museeuw - now on the market - incorporates flax fibres in its frame and fork. That's a bike made (partly) out of hemp. Talk about a "cycling high".

Before we get too excited, the resin used here is still oil-based. But biocomposite manufacture is being developed that uses plant-based lubricants, although it has yet to provide the technical properties of conventional resin for high-end uses. Other plant fibres are mooted, too. A Scottish company named Cellucomp is already selling a fishing rod using "biofibres" that it thinks could work well for bike frames. The source? A bag of carrots.

We may be some years away from a bike you can put on the compost heap when it reaches the end of its life. For one thing, the trick of creating a biodegradable bike that doesn't start mulching down before you're ready presents a significant scientific challenge. But it could be that the future really is orange.